Because they contain delphinine and other toxic alkaloids, Larkspurs are poisonous to livestock, particularly sheep. On the desert, the plants are small and bear few but beautiful blossoms. They prefer open, gravelly soil.
It is reported that the Hopi Indians grind Larkspur blossoms with corn to produce blue meal.
[Illustration: Dalea mollis Dalea spinosa Dalea formosa]
Common names: SMOKETREE, INDIGOBUSH, PEABUSH Arizona and California deserts: (_Dalea spinosa_). Blue-violet. April-June. Texas deserts: (_Dalea formosa_). Purple. March-June. Pea family. Size: Up to 10 or 12 feet tall.
Famous, although not common, throughout the frostless areas of the desert, the Smoketree, because of its gray-green, leafless, plume-like growth resembles at a distance a gray cloud of smoke hovering over a desert campfire. When in flower, in May or June, it is one of the handsomest of desert shrubs. It is always found in the bed of a sandy wash where it obtains moisture from runoff following summer showers or winter rains.
In California, it occurs in portions of both the Mohave and the Colorado Deserts, and in Arizona is restricted to the western part of the state. It is fairly abundant near Quitobaquito in the southwestern corner of Organ Pipe Cactus National Monument.
Other species of Indigobush, of which there are many, are less famous than the Smoketree, but all have purple or indigo flowers and most of them are beautiful and noticeable when in blossom. Indians used an extract from the twigs for dyeing basket material and ate the roots of _D. terminalis_.
Common names: WILD-RHUBARB, DOCK, SORREL, _CANAIGRE_ Arizona and California deserts: (_Rumex hymenosepalus_). Pink-green. March-April. Texas desert: (_Rumex mexicanus_). Pink-green. Summer. Buckwheat family. Size: Coarse perennial up to 2 feet tall.
Sturdy, conspicuous flower and seed heads together with the large leaves of these coarse, roadside plants, although hardly to be considered as beautiful, attract considerable attention and arouse the curiosity of the observer. Some species are garden weeds introduced from Europe. In the desert, the large, coarse leaves and pinkish flower stalks make quite a showing in sandy washes and along the roadsides as early as March and April. The plant is being considered as a source of tannin (from its tubers) to replace that formerly obtained from Chestnuts.